Reamer



Oct. 30, 19 23.

A,M CRACKEN REAMER Filed Sept. 3. 1921 2 Sheets-Sheet 1 Get. 30; 1923. 1 1,472,182

A. MGCRACKEN REAMER Filed Sept. 1 1921 2 Sheets-Sheet 2 Patented Oct. 30, 1923.

UNlTED STATES 1,472,182 PATENT OFFICE.

ADAM MGGRACKEN, OF LONDON, ENGLAND.

BEAMEB.

Application filed September To all whom it may concern:

Be it known that I, ADAM MoCRAoKnN, a subject of the King of Great Britain and Ireland, and a resident of London, England, have invented a. certain new and useful Improvement in Reamers, of which the following is a specification.

This invention relates to the enlarging of the lower end of holes or bore-s drilled in rocks, surface quarrying and underground mining, for the reception therein of blasting charges, and the object of the present inventi'on is the provision of a rotary tool, as hereinafter set forth for effecting such enlargement of the holes or bores, after the latter have been made by the ordinary drill heretofore in use.

A tool in accordance with the invention consists of a steel bar with a longitudinal and centrally disposed bore therethrough, said bore being tapped at its upper end to receive the threaded part of a feed rod, and at its lower end enlarged for the reception therein of a slidable, but non-rotatable, cylindrical and fork-shaped block.

The feed rod is, at its lower end, rotatably and dotachably secured to the base part of the cylindrical block aforesaid, and in the fork of said block a pair of cutters are slidably mounted, said cutters being provided. with lugs arranged at an angle of degrees or thereabouts, slidaibly fitting in grooves in the faces of the fork, the grooves running at the same angle as the lugs, the arrangement being such that on forcing down the block, by screwing down the feed rod, said cutters are g'gradually forced outwards through radially disposed slots formed in the wall of the enlarged part of the bar, said enlargement being closed by means of a removable nipple or plug which forms a level base for the bottom of the cutters to slide on.

The invention will now be fully described with reference to the accompanying drawings, in which Figure l is a sectional elevation of the tool; and

Figure 1 is a view showing a means for connecting said tool to a prime mover.

Figure 2 is a cross-section through line 2-2 of Figure 1, the tool being shown with the cutters closed.

Figure 3 is a sectional elevation of the cutter end of the tool, taken at right angles 1, 1921. Serial No. 497,654.

to the view shown in Figure l, and showing the cutters expanded; and,

Figure 3% is a sectional plan view illustrative of the saddle pin hereinafter referred to.

Figure 4 is a sectional plan view of the cutter end of the tool, through line M, Figure 3. v

Similar letters of reference indicate like parts where occurring.

In carrying this invention into effect, a round bar a, Figure 1, of mild steel (which may be case-hardened) bored centrally the whole of its length and of a diameter and length to suit the diameter and depth of the hole required, is made use of as the holder for the cutters, the upper end of which holder can be adapted to existing power appliances in the manner herein described and shown in Figure 1.

The upper end a? of the bar a is of hex a-gona-l shape, and over such hexagonal end and a portion of the cylindrical part ofthe bar av therebelow, there is fitted and secured the lower end of a skeleton-like box or cage a, said box or cage (1 which is of a length to suit requirements, being at its upper end, fixedly connected to the spindle a which receives rotary motion from the prime mover, said spindle a? being raised and lowered by graduated stages when the tool is making its enlarging transverse cuts.

The bore is tapped at its upper end a (see Figure 1) and a. feeding rod 6 is passed through the bore to the lower end of the bar a. The feeding rod 6 is threaded at its upper end I) for engagement with the threaded end a of the bar a, and at its lower end is connected to a mild steel cylindrical block 0 casehardened and fitting in an enlargement a of the bore in the bar a The wedge portions of the block 0, which, as shown in Fig ure 1, is forked to receive the cutters (Z are constituted by the grooves e arranged at an angle of 60 degrees or thereabouts on the inside faces of the forked member 0, and in said grooves e slidably fit the lugs cl on the cutters cl, said lugs being arranged at the same angle as said grooves.

The length of the cylinder 0 is just suf ficient to clear the face of the bottom of the bar. At the base of the cylinder 0 a suit able hole is drilled for the end of the feed rod 6 and small holes are drilled to take a saddle pin f -Figures 8 and 3 forming 7 opposite directions;

a swivel joint between feed rod and cylinder, whilst rotation 02B said cylinder is prevented by means of a set screw passed into a groove formedin the exterior surface of said cylinder g The cutters (Z are of such a size thattheir cutting edges are flush with the circuin'feu throughtheopenings of the box orcage a to engagein. one or the other of the holes 5 in the head'o f the feed rodlb, thus forcing the cylinder 0 downwards, gradually pushed outwards, transversely of'the: tool, through the slots inthe wall offthe bar ax; until stoppedby the limit of the size of'the niechanisnn At; this stage the back edge of the cutters d still ov'erlap*fsee Figure 4.

After the first recess is out, the barnmay be withdrawn to. nearly the height ol the plates, and the cut agarin made, and this .operation may be repeated to whatever lerigth of countersink is required.

y rotatingthe screw 1)" in the opposite direction the eylin'derc drawnupwards, and at the same time, by the"grooves a in the faces of the forl'r of the'cylin'der being engaged by thevlugs djon the cutters d, said cutters are gradually with drawn until they recede withinthewa'lls or the round bar'a'-- as in Figures 1 and Q -wlieir the bar 12' can be with'dravmfand the" here can be cleaned out.

A nipple or plug 9- formed with a recessed internal thread? which engages an externalthread on the lower end of the bar a, serves to strengthen said bar eat that part, and by leavinga centre of metal in said plug 9 to approximately fit the internal bore of the bar a and lie flush with the bottom of the cutting blades 'd, a smooth level base is provided upon which the cutting blades d slide: The outer end "(/"ofthe nipple or plug-g is prolonged to enable debris blades, the nipple or plug 9 is unscrewed, the feed rod Z) is screwed down until the cylinder 0 is entirely exposed and then with a pointed instrument the saddle pin can be: levered out andthe cylinder taken olll including a bar having a central longi'tudb nal bore, the upper end of which threaded and the lower end of which is enlarged and provided with lateral slots, a feed rod having a threaded portion screwing into said threads of the bore; a cylindrical and fork-shaped block slida-bly but nonu'otutably mounted in said enlarged lower end of the bore and the inside faces of the forked-"portion of the block havin rooves arranged at an angle or approxinnitely co degrees, means for rotatably and detachably securing said feed rod to said cylindrical block, a pair of radially disposed cutters slidab'ly mounted in the fork of the block, lugs on the cutters arranged at approximately an angle of degrees and being slidable in said grooves, and a removable plug enclosing the enlarged end of the bar and forming alevel base for the bottom edges of the cutters to slide upon.

2. A rotary tool for the purpose set forth including a bar'having a central horizontal bore formed with threads at its upper end and the lower end thereof being enlarged and provided with lateral slots, a feed rod having a threaded portion adapted to en gage with the threads of the bore, a eylin drical' fork shaped block carried by the lower end of the rod and arranged in the enlarged lower end of the bore, means for detachably and rotatably securing said feed rod to said block, a plug enclosing the enlarged end of the bar, and cutters slidahly interlocked with the inner faces of the fork shaped cylindrical block and bearing against said plug, said cutters projecting through the lateral slots of the bar.

In testimony whereof I have alli'xed my signature hereto this 21 d av of June, 1921.

ADAM MoCRA CKE N. 

